A phase-change thermal device is a device that is filled (i.e., charged) with a working fluid that changes to a vapor in response to thermal energy. Example phase-change thermal devices include, but are not limited to, a thermal switch or diode device, a vapor chamber, a heat pipe, and a thermal ground plane. In these devices, a chamber is filled with the working fluid. However, in miniature phase-change thermal device (e.g., devices charged with a working fluid volume of less than or equal to 1 ml), it may be very difficult to control the amount of working fluid injected into the device. In many cases, the volume of working fluid should be precisely controlled so that the phase-change thermal device may operate as desired.
Further, in the case of a thermal switch device, the vacuum level within the thermal switch device is controlled so that the thermal switch devices switches from relatively low thermal conductivity to relatively high thermal conductivity at a desired temperature. The thermal switch device is sensitive to the amount of non-condensable gas left within the chamber. Thus, the presence of non-condensable gas within the thermal device may lead to a non-controllable switching temperature of the thermal switch device.
Accordingly, a need exists for alternative systems and methods for degassing and charging phase-change thermal devices.